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author | Joe Thornber <ejt@redhat.com> | 2019-01-15 13:27:01 -0500 |
---|---|---|
committer | Mike Snitzer <snitzer@redhat.com> | 2019-01-15 16:10:41 -0500 |
commit | d445bd9cec1a850c2100fcf53684c13b3fd934f2 (patch) | |
tree | abca30179b3fa5355959344f50c57dce9213ef55 /drivers/md/dm-thin-metadata.c | |
parent | 1856b9f7bcc8e9bdcccc360aabb56fbd4dd6c565 (diff) | |
download | linux-stable-d445bd9cec1a850c2100fcf53684c13b3fd934f2.tar.gz linux-stable-d445bd9cec1a850c2100fcf53684c13b3fd934f2.tar.bz2 linux-stable-d445bd9cec1a850c2100fcf53684c13b3fd934f2.zip |
dm thin: fix passdown_double_checking_shared_status()
Commit 00a0ea33b495 ("dm thin: do not queue freed thin mapping for next
stage processing") changed process_prepared_discard_passdown_pt1() to
increment all the blocks being discarded until after the passdown had
completed to avoid them being prematurely reused.
IO issued to a thin device that breaks sharing with a snapshot, followed
by a discard issued to snapshot(s) that previously shared the block(s),
results in passdown_double_checking_shared_status() being called to
iterate through the blocks double checking their reference count is zero
and issuing the passdown if so. So a side effect of commit 00a0ea33b495
is passdown_double_checking_shared_status() was broken.
Fix this by checking if the block reference count is greater than 1.
Also, rename dm_pool_block_is_used() to dm_pool_block_is_shared().
Fixes: 00a0ea33b495 ("dm thin: do not queue freed thin mapping for next stage processing")
Cc: stable@vger.kernel.org # 4.9+
Reported-by: ryan.p.norwood@gmail.com
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers/md/dm-thin-metadata.c')
-rw-r--r-- | drivers/md/dm-thin-metadata.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/md/dm-thin-metadata.c b/drivers/md/dm-thin-metadata.c index 20b0776e39ef..ed3caceaed07 100644 --- a/drivers/md/dm-thin-metadata.c +++ b/drivers/md/dm-thin-metadata.c @@ -1678,7 +1678,7 @@ int dm_thin_remove_range(struct dm_thin_device *td, return r; } -int dm_pool_block_is_used(struct dm_pool_metadata *pmd, dm_block_t b, bool *result) +int dm_pool_block_is_shared(struct dm_pool_metadata *pmd, dm_block_t b, bool *result) { int r; uint32_t ref_count; @@ -1686,7 +1686,7 @@ int dm_pool_block_is_used(struct dm_pool_metadata *pmd, dm_block_t b, bool *resu down_read(&pmd->root_lock); r = dm_sm_get_count(pmd->data_sm, b, &ref_count); if (!r) - *result = (ref_count != 0); + *result = (ref_count > 1); up_read(&pmd->root_lock); return r; |